From 2a6e44dcb0ff041b984edd2d9c7dd8e57e72058a Mon Sep 17 00:00:00 2001
From: SingleCopy <rudd.andy@gmail.com>
Date: Tue, 16 Jun 2026 14:05:15 +0100
Subject: [PATCH] Support which segment is selected via the segment/seg args

---
 src/DebugInterface/Symbols/CDebugSymbols.cpp |  5 +++++
 src/DebugInterface/Symbols/CDebugSymbols.h   |  1 +
 src/Tools/C64CommandLine.cpp                 | 19 +++++++++++++++++++
 src/Tools/C64CommandLine.h                   |  3 ++-
 src/Tools/C64SettingsStorage.cpp             |  1 +
 src/Tools/C64SettingsStorage.h               |  1 +
 6 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/src/DebugInterface/Symbols/CDebugSymbols.cpp b/src/DebugInterface/Symbols/CDebugSymbols.cpp
index 293eab98..1bd7d93d 100644
--- a/src/DebugInterface/Symbols/CDebugSymbols.cpp
+++ b/src/DebugInterface/Symbols/CDebugSymbols.cpp
@@ -1518,6 +1518,11 @@ void CDebugSymbols::DeactivateSegment()
 	guiMain->UnlockMutex();
 }
 
+void CDebugSymbols::SetPreviousSegment(CSlrString* segmentName)
+{
+	this->previousSegmentName = segmentName;
+}
+
 //
 void CDebugSymbols::SelectNextSegment()
 {
diff --git a/src/DebugInterface/Symbols/CDebugSymbols.h b/src/DebugInterface/Symbols/CDebugSymbols.h
index d02c7bb9..afe801bf 100644
--- a/src/DebugInterface/Symbols/CDebugSymbols.h
+++ b/src/DebugInterface/Symbols/CDebugSymbols.h
@@ -48,6 +48,7 @@ class CDebugSymbols
 	void ActivateSelectedSegment();
 	void ActivateSegment(CDebugSymbolsSegment *segment);
 	void DeactivateSegment();
+	void SetPreviousSegment(CSlrString* segmentName);
 	
 	//
 	void SelectNextSegment();
diff --git a/src/Tools/C64CommandLine.cpp b/src/Tools/C64CommandLine.cpp
index 030eb8b6..1e2d5f4c 100644
--- a/src/Tools/C64CommandLine.cpp
+++ b/src/Tools/C64CommandLine.cpp
@@ -635,6 +635,11 @@ void c64PerformStartupTasksThreaded()
 			debugInterface->symbols->DeleteAllSymbols();
 			debugInterface->symbols->ParseSourceDebugInfo(c64SettingsPathToDebugInfo);
 		}
+
+		if (c64SettingsDefaultSegment != NULL)
+		{
+			debugInterface->symbols->SetPreviousSegment(c64SettingsDefaultSegment);
+		}
 	}
 
 	// skip any automatic loading if jukebox is active
@@ -891,6 +896,12 @@ void C64DebuggerParseCommandLine2()
 			char *arg = c64ParseCommandLineGetArgument();
 			c64SettingsPathToDebugInfo = new CSlrString(arg);
 		}
+		else if (!strcmp(cmd, "segment") || !strcmp(cmd, "seg"))
+		{
+			char *arg = c64ParseCommandLineGetArgument();
+			LOGD("default segment='%s'", arg);
+			c64SettingsDefaultSegment = new CSlrString(arg);
+		}
 		else if (!strcmp(cmd, "autojmp") || !strcmp(cmd, "autojump"))
 		{
 			cmdLineOptionDoAutoJmp = true;
@@ -1102,6 +1113,14 @@ void C64DebuggerPassConfigToRunningInstance()
 		byteBuffer->PutSlrString(c64SettingsPathToDebugInfo);
 	}
 
+	if (c64SettingsDefaultSegment)
+	{
+		LOGD("c64SettingsDefaultSegment");
+		c64SettingsPathToWatches->DebugPrint("c64SettingsDefaultSegment=");
+		byteBuffer->PutU8(C64D_PASS_CONFIG_DATA_DEFAULT_SEGMENT);
+		byteBuffer->PutSlrString(c64SettingsDefaultSegment);
+	}
+
 	if (c64CommandLineHardReset)
 	{
 		byteBuffer->PutU8(C64D_PASS_CONFIG_DATA_HARD_RESET);
diff --git a/src/Tools/C64CommandLine.h b/src/Tools/C64CommandLine.h
index d92f58a8..3bd785f7 100644
--- a/src/Tools/C64CommandLine.h
+++ b/src/Tools/C64CommandLine.h
@@ -40,7 +40,8 @@ typedef enum c64d_pass_config_data_e {
 	C64D_PASS_CONFIG_DATA_HARD_RESET,
 	C64D_PASS_CONFIG_DATA_FULL_SCREEN,
 	C64D_PASS_CONFIG_DATA_SELECT_EMULATOR,
-	C64D_PASS_CONFIG_DATA_DETACH_EVERYTHING
+	C64D_PASS_CONFIG_DATA_DETACH_EVERYTHING,
+	C64D_PASS_CONFIG_DATA_DEFAULT_SEGMENT
 } c64d_pass_config_data_t;
 
 
diff --git a/src/Tools/C64SettingsStorage.cpp b/src/Tools/C64SettingsStorage.cpp
index 371d638f..905db7d8 100644
--- a/src/Tools/C64SettingsStorage.cpp
+++ b/src/Tools/C64SettingsStorage.cpp
@@ -209,6 +209,7 @@ CSlrString *c64SettingsPathToSymbols = NULL;
 CSlrString *c64SettingsPathToBreakpoints = NULL;
 CSlrString *c64SettingsPathToWatches = NULL;
 CSlrString *c64SettingsPathToDebugInfo = NULL;
+CSlrString *c64SettingsDefaultSegment = NULL;
 
 bool c64SettingsUseNativeEmulatorMonitor = false;
 
diff --git a/src/Tools/C64SettingsStorage.h b/src/Tools/C64SettingsStorage.h
index eab4c2bd..90f4e6b7 100644
--- a/src/Tools/C64SettingsStorage.h
+++ b/src/Tools/C64SettingsStorage.h
@@ -202,6 +202,7 @@ extern CSlrString *c64SettingsPathToSymbols;
 extern CSlrString *c64SettingsPathToWatches;
 extern CSlrString *c64SettingsPathToBreakpoints;
 extern CSlrString *c64SettingsPathToDebugInfo;
+extern CSlrString *c64SettingsDefaultSegment;
 
 extern bool c64SettingsUseNativeEmulatorMonitor;